The present disclosure relates to turbomachinery, such as gas turbine engines, having two surfaces which move relative to each other and which have features on the surfaces which create variations in pressure within a cavity between the two surfaces.
The rim cavity regions of turbomachinery applications, specifically within the turbine and compressor portions of a gas turbine engine, can pose significant challenges to the performance of the turbomachinery. For example, within turbines, the rim cavity regions should be kept cool with respect to the high main-flow temperatures in order to preclude thermal damage and to help extend component life. Cold purge air may be introduced into cavities to keep out main gas path air. However, the introduction of such purge air may reduce turbine efficiency. Within a compressor, the rim cavity may be pressurized to prevent high-pressure air from leaking forward. Improvements to the rim cavity in terms of reduced purge flow and/or cavity wall temperature are desirable since they make a direct improvement to the turbomachinery.